Heretofore it has been a common industrial practice in the United States to manufacture friction brakes subassemblies such as the friction brake shoes and friction brake pads typically utilized in automotive vehicle brake systems to first form a friction material particulate mixture having an included phenolic resin binder into a cured brake lining shape of specific configuration and afterwards join the cured brake lining shape to a cooperating brake member backing plate by mechanical fasteners such as rivets or by a suitable adhesive such as a cured phenolic resin, a cured elastomeric rubber, or a like adhesive. The friction material particulate mixture cured brake lining shape is typically constituted of inorganic compound particles, organic compound particles, metallic particles, reinforcing fibers, and sometimes carbon particles, in addition to the phenolic resin binder.
Another form of conventional friction brake member, sometimes referred to as an integrally molded brake shoe or integrally molded brake pad, is manufactured using a method wherein the required adhesive material is applied to the brake subassembly backing plate element in its uncured condition and the friction material brake lining with phenolic resin binder is placed in contact with the applied uncured adhesive. The adhesive material is subsequently cured simultaneously with the necessary curing of the brake lining friction material particulate composition mixture.
I have discovered that both the need for multi-step resin curing processes and the need for separate particle binder resin and adhesive resin systems can be avoided in the manufacture of friction brake subassemblies to economic advantage by utilizing a friction material composition wherein the included uniformly dispersed resin binder system functions satisfactorily both as a composition particle binder and as an adhesive joining the brake lining cured composition to its brake backing plate element.
Other advantages of my invention will become apparent during a careful consideration of the detailed information which follows.